8 math 550 percent word problems 2
TRANSCRIPT
Percent Word Problems Handout
Revised @2009 MLC page 1 of 8
Percent Word Problems Ratio and proportion method
Here are several aids that will help you solve word problems:
1. Make sure you understand the question that is asked
2. Sort out the information to make a basic percent problem, such
as “30% of what is 17?”
3. Sometimes, you will have to subtract or add some of the numbers.
4. The base will always be the original number, price, or total.
Some examples of percent word problems.
A baseball pitcher won 80% of the games he pitched. If he pitched 35
ballgames, how many games did he win?
80% of 35 is what?
35100
80
Jerry, an electrician, worked 7 months out of the year. What percent
of the year did he work? (round answer to the nearest hundredth)
What percent of 12 is 7? 12 months = 1 year
12
7
100
1. Multiply the opposites
80 x 35 = 2800
2. Divide by the remaining number
282800100
28 games
1. Multiply the opposites
7 x 100 = 700
2. Divide by the remaining number
58.33700.0012
58.33% (rounded to hundredth)
Percent Word Problems Handout
Revised @2009 MLC page 2 of 8
Sometimes the information needed to solve a percent word problem is not
stated directly. You will need to sort out the numbers given in the problem.
Organizing all the information into a box format will help you see what
numbers you have and what you need.
Some examples.
There are 28 students in a class. Sixteen of those students are men.
What percent of the class are women? (Round to the nearest tenth)
Men % 16
Women % 12
Total 100% 28
12 is what % of 28?
28
12
100
`
Donovan took a math test and got 35 correct and 10 incorrect answers.
What was the percentage of correct answers? (Round to the nearest
hundredth)
Correct answers % 35
Incorrect answers % 10
Total answers 100% 45
35 is what % of 45?
45
35
100
1. Multiple the opposites
100 x 12 = 1200
2. Divide by the remaining number
42.851200.0028
42.9%
28 total students
-16 men
12 women
35 correct answers
+10 incorrect answers
45 total answers
1. Multiple the opposites
100 x 35 = 3500
2. Divide by the remaining number
77.7773500.00045
77.78% (rounded to hundredth)
Percent Word Problems Handout
Revised @2009 MLC page 3 of 8
Percent Word Problems
Directions: Set up a basic percent problem. Sometimes you will have to do
extra steps to solve the problem. Follow rounding directions. Answers and
solutions start on page 6.
1) A student earned a grade of 80% on a math test that had
20 problems. How many problems on this test did the
student answer correctly? (round to the nearest whole
number)
2) There are 36 carpenters in a crew. On a certain day, 29
were present. What percent showed up for work? (round to
the nearest tenth)
3) A metal bar weighs 8.15 ounces. 93% of the bar is silver.
How many ounces of silver are in the bar? (round to the
nearest thousandth)
4) A woman put $580 into a savings account for one year. The
rate of interest on the account was 6½%. How much was the
interest for the year in dollars and cents? (Round to the
nearest cent)
Percent Word Problems Handout
Revised @2009 MLC page 4 of 8
5) A student answered 86 problems on a test correctly and
received a grade 98%. How many problems were on the test,
if all the problems were worth the same number of points?
(Round to the nearest whole number)
6) Manuel found a wrecked Trans-Am that he could fix. He
bought the car for 65% of the original price of $7200.
What did he pay for the car? (Round to nearest dollar)
7) Pamela bought an electric drill at 85% of the regular price.
She paid $32.89 for the drill. What was the regular price?
(Round to the nearest cent)
8) A crew is made up of 8 men; the rest are women. 663
2% of
the crew are men. How many people are in the crew?
9) Ben earns $12,800 a year. About 15% is taken out for taxes.
How much is taken out for taxes?
Percent Word Problems Handout
Revised @2009 MLC page 5 of 8
10) At a sale, shirts were sold for $15 each. This price was 80%
of their original price. What was the original price?
11) There are 32 students in a class. Nine of those students are
women. What percent are men? (round to the nearest tenth)
12) The Royals softball team played 75 games and won 55 of
them. What percent of the games did they lose? (round to
the nearest tenth)
Percent Word Problems Handout
Revised @2009 MLC page 6 of 8
Answer Key
1. 20100
80
Multiply the opposites:
80 x 20 = 1600
Divide by the remaining number: 16
1600100
16 problems
2. 36
29
100
Multiply the opposites:
29 x 100 = 2900
Divide by the remaining number: 55.80
00.290036
80.6%
3. 8.15100
93
Multiply the opposites:
93 x 8.15 = 757.95
Divide by the remaining number: 5795.7
9500.757100
7.580 ounces
4. 580100
216
Multiply the opposites:
6 ½ x 580 = 3770
Divide by the remaining number: 70.37
00.3770100
$37.70
5. 86
100
98
Multiply the opposites:
100 x 86 = 8600
Divide by the remaining number: 7.87
0.860098
88 problems (rounded to nearest whole)
Percent Word Problems Handout
Revised @2009 MLC page 7 of 8
6. 7200100
65
Multiply the opposites:
65 x 7200 = 468,000
Divide by the remaining number: 4680
468000100
$4680
7. 32.89
100
85
Multiply the opposites:
100 x 32.89 = 3289
Divide by the remaining number: 694.38
000.328985
$38.69
8. 8
1003
266
Multiply the opposites:
100 x 8 = 800
Divide by the remaining number:
1
12
200
3
1
800
3
200
1
800
3266800
12
9. 12,800100
15
Multiply the opposites:
15 x 12,800 = 192,000
Divide by the remaining number: 1920
192000100
$1920
10. 15
100
80
Multiply the opposites:
100 x 15 = 1500
Divide by the remaining number: 75.18
00.150080
4
1
Percent Word Problems Handout
Revised @2009 MLC page 8 of 8
$18.75
11.
Total 100% 32
Men 23
Women 9
32
23
100
23
9
32
Multiply the opposites:
100 x 23 = 2300
Divide by the remaining number: 71.87
2300.0032
71.9%(rounded to nearest tenth)
12.
Total 100% 75
Won 55
Lost 20
75
20
100
20
55
75
Multiply the opposites:
100 x 20 = 2000
Divide by the remaining number: 26.667
2000.00075
26.7% games lost (rounded to tenth)